United States
[Environmental Protection
Agency
Atmospheric Research and
Exposure Assessment Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S3-90/005 Mar. 1990
&EPA Project Summary
Development and
Validation of a Test
Method for Formaldehyde
Emissions
E. D. Estes, W. F. Gutknecht, D. L Hardison, G. B. Howe, R. K. M. Jayanty, and
J. A. O'Rourke
Formaldehyde has been identified
as a suspect carcinogen and may be
regulated in the future as a
hazardous air pollutant under Section
112 of the Clean Air Act. The full
report details the field validation of a
test method for sampling and
analyzing formaldehyde emissions
from stationary sources. Three
potential source methods were
evaluated. One method, the basic
peroxide impinger/ion chroma-
tography (1C) method is based upon
the dissolution and oxidation of
formaldehyde in the impinger reagent
to form formate ion, which is
measured by 1C. The second method
is a dinitrophenylhydrazine-coated
(DNPH) cartridge/high performance
liquid chromatography (HPLC)
method, which is based on the
reaction of formaldehyde with 2,4-
DNPH and subsequent analysis of the
hydrazone derivative by HPLC. The
third method, the DNPH
irnpinger/HPLC method extends the
range of the cartridge method
through the use of higher capacity
DNPH impinger solutions.
Field testing of the methods were
conducted at two different sites. At a
formaldehyde manufacturing plant,
where formaldehyde levels were high
(> 100 mg/cu m), samples were
collected using the basic peroxide
impinger method and the DNPH
impinger method. At a formaldehyde
user facility, where formaldehyde
levels were low, samples were
collected using the DNPH-coated
cartridge method and the DNPH
impinger method.
A statistical evaluation indicates
that the DNPH impinger method is
acceptable for determining both low
and high concentrations of
formaldehyde. Because of its range,
this method is recommended as the
reference method for determination
of formaldehyde in source emissions.
The full report is submitted in
fulfillment of EPA Contract Nos. 68-
02-4125 and 68-02-4550 by the
Research Triangle Institute under the
sponsorship of the U.S.
Environmental Protection Agency.
The report covers a period from
February 1987, through April 1989.
This Project Summary was
developed by EPA's Atmospheric
Research and Exposure Assessment
Laboratory, Research Triangle Park,
NC, to announce key findings of the
research project that is fully
documented in a separate report of
the same title (see Project Report
ordering information at back).
Introduction
Formaldehyde has been identified as a
suspect carcinogen and may be
regulated in the future as a hazardous air
pollutant under Section 112 of the Clean
Air Act. The U. S. Environmental
Protection Agency (USEPA) has an
ongoing program to evaluate and
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Methods Evaluated
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formaldehyde concpnt«f-
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1
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Sample Collection
equipped w a o
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HPLC
°op and a
. The DNPH
gravity ,eed us,ng 6
eluate was collectprt ,
'lasks and dH^d h
Measurements we re mil mark
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Preparation
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prior to
DNPH
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increased. The average BSD for these
data was 1.9 percent with a range of 0.9
to 3.9 percent. The respective, pooled
standard deviations for the impinger and
cartridge data were calculated to be 4.9
and 2.1 percent. A comparison of the
means again using analysis of variance
indicated the methods to be significantly
different at the 95 percent confidence
level. The average difference was
calculated to be 0.079 mg/cu m or 7.5
percent, with the DNPH cartridges
producing demonstrably higher values.
Several parameters which collectively
may have contributed to this difference
include slightly lower collection efficiency
in the impingers, loss from the impingers
(in the form of aerosol), and some minor
interferent or formaldehyde background
on the cartridges. The average recovery
for the DNPH-formaldehyde derivative
spike at the user site was 92 percent,
which supports the first of the two
possible reasons given for the difference
between the methods.
Conclusion
The best precision was obtained with
the DNPH-coated cartridge/HPLC
method, which had a pooled standard
deviation of 0.023 mg/cu m. The method
was also the easiest to use, with no
possibility of sample containers breaking
or reagents spilling in the field. However,
the capacity of the cartridge was
exceeded quickly at the high
concentrations (> 100 mg/cu m) of
formaldehyde generally present at the
formaldehyde manufacturing facilities.
The DNPH impinger/HPLC method was
tested at both the formaldehyde
manufacturing site and the formaldehyde
user site. A statistical evaluation indicates
that this method is acceptable for
determining both low and high
concentration levels of formaldehyde.
Because of its poor detection limit, the
basic peroxide impinger/IC method was
found to b e unsuitable for the
determination of very low levels of
formaldehyde (0.5 to 5 mg/cu m) such as
those found at formaldehyde user sites.
The method also yielded unacceptable
results for the very high concentrations of
formaldehyde (> 500 mg/cu m)
sometimes found at formaldehyde
manufacturing facilities, because the
formaldehyde is not completely oxidized
to formate ion. The method does show
potential at intermediate levels (50-300
mg/cu m), and, because the reagents
used are safer and easier to prepare in
the field than those used for the DNPH
impinger method, it is recommended that
the oxidation reaction be studied further.
The major objective of the study was to
develop and recommend a single method
for sampling and analysis of
formaldehyde over a wide range of
concentrations (< 1 mg/cu m to > 500
mg/cu m). The DNPH impinger/HPLC
method meets this requirement and is
therefore recommended as the reference
method. However, in view of the excellent
precision obtained for the DNPH-coated
cartridge method and its ease of use, it is
recommended that this method be
approved as an alternate when low levels
of formaldehyde are expected.
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E. D. Estes, W. F. Gutknecht, D. L. Hardison, G. B. Howe, R. K. M. Jayanty and J.
A. O'Rourke are with Research Triangle Institute, Research Triangle Park, NC
27709.
Jimmy C. Pau is the EPA Project Officer (see below).
The complete report, entitled "Development and Validation of a Test Method for
Formaldehyde Emissions," (Order No. PB-90-183-419AS; Cost: $17.00
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Atmospheric Research and Exposure Assessment Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States Center for Environmental Research
Environmental Protection Information
Agency Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S3-90/005
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